Ambassadors to Washington warn that the GOP-Democratic divide is endangering America’s national security.

When I asked the European ambassador to talk to me about America’s deepening partisan divide, I expected a polite brushoff at best. Foreign diplomats are usually loath to discuss domestic U.S. politics.

Instead, the ambassador unloaded for an hour, warning that America’s poisonous politics are hurting its security, its economy, its friends and its standing as a pillar of democracy and global stability.

The U.S. is a “fat buffalo trying to take a nap” as hungry wolves approach, the envoy mused. “I can hear those Champagne bottle corks popping in Moscow — like it’s Christmas every fucking day.”

As voters cast ballots in the Iowa caucuses Monday, many in the United States see this year’s presidential election as a test of American democracy. But, in a series of conversations with a dozen current and former diplomats, I sensed that to many of our friends abroad, the U.S. is already failing that test.